Constrained tuning: Difference between revisions

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Definition: improve the formulation
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== Definition ==
== Definition ==
Given a temperament [[mapping]] ''V'' and the [[just tuning map]] ''J'', we specify a weight–skew transformation, represented by transformation matrix ''X'', and a ''q''-norm. Suppose the tuning is constrained by the eigenmonzo list ''M''<sub>''I''</sub>. The goal is to find the generator list ''G'' by
Given a [[temperament mapping matrix]] ''V'' and the [[just tuning map]] ''J'', we specify a weight–skew transformation, represented by transformation matrix ''X'', and a ''q''-norm. Suppose the tuning is constrained by the eigenmonzo list ''M''. Let ''G'' denote the generator tuning map, we want to


Minimize
$$
 
\begin{align}
<math>\displaystyle \norm{GV_X - J_X}_q </math>
& \text{find} && G \\
 
& \text{that minimizes} && \lVert GV_X - J_X \rVert_q \\
subject to
& \text{subject to} && (GV - J)M = O
 
\end{align}
<math>\displaystyle (GV - J)M_I = O </math>
$$


where (·)<sub>''X''</sub> denotes the variable in the weight–skew transformed space, found by
where (·)<sub>''X''</sub> denotes the variable in the weight–skew transformed space, found by


<math>\displaystyle
$$
\begin{align}
\begin{align}
V_X &= VX \\
V_X &= VX \\
J_X &= JX
J_X &= JX
\end{align}
\end{align}
</math>
$$


The problem is feasible if
The problem is feasible if
# rank(''M''<sub>''I''</sub>) ≤ rank(''V''), and
# rank(''M'') ≤ rank(''V''), and
# The subgroups of ''M''<sub>''I''</sub> and N (''V'') are {{w|linear independence|linearly independent}}.
# The subgroups of ''M'' and N (''V'') are {{w|linear independence|linearly independent}}.


== Computation ==
== Computation ==